Heat shock protein response in phosphorus-deficient heat-stressed broiler chickens.

1. During acute in vivo heat stress, a normal heat shock protein (HSP) response was not inducible in chickens deficient in inorganic phosphorus (P(i)-deficient). 2. Small quantities of HSP 70 and HSP 90 were induced, but little or no HSP 23 was induced in P(i)-deficient chickens compared to P(i)-adequate chickens. 3. Increased susceptibility of P(i)-deficient chickens to acute heat stress was attributed to their inability to produce an adequate HSP response.